Ipomoea batatas is a member of the morning glory family Convolvulaceae. This species is grown worldwide and it exhibits a wide range of plant forms and colors. The cultivated members of Ipomoea batatas grown by fanners worldwide are commonly produced for consumption of their nutritious, enlarged storage roots. These types typically produce a fast growing green vine that has a wide variety of leaf shapes ranging from palmate and deeply lobed, to cordate or triangular shaped leaves with no lobes.
Like their edible forms, Ipomoea batatas ornamental sweetpotato plants are a heat-loving, drought-tolerant, perennial vine typically grown as an annual. However, ornamental sweetpotato plants are distinguished from the edible cultivated forms in that they possess unique foliage colors, leaf shapes, and growth habits, which have significant value in the ornamental marketplace.
Ornamental sweetpotatoes are desirable in the landscape and ornamental industries because their foliage comes in a wide variety of colors (e.g. pale yellow to dark purple with some exhibiting temporal and individual leaf color variegation patterns) and plant shapes (e.g. mounded and very compact to prostrate and highly spreading). They can be grown as a potted plant and/or in a mixed planting format, and they have the ability to cover a large space or hang over walls and decorative pots creating brightly colored and textured backdrops in gardens and patios. Most ornamental sweetpotatoes grow and last the entire growing season and they require little maintenance. Moreover, these plants have few insect or disease problems.
To meet the growing horticultural demand for ornamental sweetpotatoes, it is desirable to produce new cultivars of ornamental sweetpotato with new or improved foliage colors, variegation patterns, leaf shapes, and plant architectures. In addition, it would be advantageous to develop cultivars of ornamental sweetpotato exhibiting a more compact growth that do not out-compete other species in mixed containers.
‘NCORNSP-025SCK’ was bred to meet the increasing demand for new ornamental sweetpotatoes. ‘NCORNSP-025SCK’ is a compact, non-twining, semi-upright variety producing many short shoots. It is distinguishable from other Ipomoea batatas cultivars by its yellow-green palmate 3-5 moderately lobed leaves, a compact habit and semi-erect mounding plant architecture. The yellow-green leaves, short internodes, and the plant architecture makes ‘NCORNSP-025SCK’ unique amongst the current ornamental sweetpotatoes in the marketplace. ‘NCORNSP-025SCK’ exhibits very good vigor and is very well branched. In greenhouse and field trials conducted since 2015 ‘NCORNSP-025SCK’ has been shown to be much less vigorous than Ipomoea batatas cultivars ‘Margarita’ (unpatented) and ‘Blackie’ (unpatented) and is suitable for use as a landscape or containerized plant. Of the common cultivars of ornamental sweetpotato, ‘NCORNSP-025SCK’ is best compared with ‘Sweet Caroline Light Green’ (U.S. Plant Pat. No. 15,028) and ‘NCORNSP-012EMLC’ (U.S. Plant Pat. No. 21,744) cultivars. Like ‘Sweet Caroline Light Green’, ‘NCORNSP-025SCK’ has yellow-green leaves and a moderately compact habit. However, the habit of ‘NCORNSP-025SCK’ is more compact and erect than ‘Sweet Caroline Light Green’, which is slightly trailing. ‘NCORNSP-012EMLC’ has very deeply lobed leaves, with 5-7 lobes. ‘NCORNSP-025SCK’ has moderately lobed leaves, with 3-5 lobes. The production of flowers by ‘NCORNSP-025SCK’ is infrequent under short day conditions.
Lineage. ‘NCORNSP-025SCK’ (breeding designation NC8995-001ORN) originated from a conventional cross between the proprietary Ipomoea batatas breeding lines NCORN8555-004ORN (the female parent; not patented) and NC8524-003ORN (the male parent; not patented). Botanical seed was harvested from the NCORN8555-004ORN x NC8524-003ORN cross and other ornamental sweetpotato lines planted in our winter greenhouse-crossing block between September of 2013 and March of 2014 in Raleigh, N.C. NC8555-004ORN resulted from open pollinated seed harvested from the proprietary Ipomoea batatas breeding line NC8241-008ORN (the female parent; not patented). NC8524-003ORN resulted from open pollinated seed harvested from the proprietary Ipomoea batatas breeding line NC7840-059ORN (the female parent; not patented). Botanical seed from the NCORN8555-004ORN x NC8524-003ORN cross was planted in the greenhouse in February of 2015. The first cycle of selection on the materials derived from the NCORN8555-004ORN x NC8524-003ORN cross was exercised at the seedling tray stage and survivors were transferred to a single 6-inch pot, which was then maintained in a virus-free greenhouse. Cuttings (2 each) were taken from the plants in April and planted in the field as 2-plant unreplicated plots during mid-June 2015. The single, individual plant now known as ‘NCORNSP-025SCK’ was selected Aug. 31, 2015 because of its combination of exceptional features, and it has been propagated asexually as vegetative material from the original 6-in pot in the sweetpotato breeding greenhouse and via tissue culture in Raleigh, N.C. since that time since that time.
Asexual Reproduction. Since its selection, Ipomoea batatas ‘NCORNSP-025SCK’ has been asexually reproduced in North Carolina predominantly by vegetative propagation of vine cuttings. Successively, there have been six cycles of vegetative propagation, one cycle of tissue culture micropropagation, and multiple vegetative propagation cycles to increase the plant population. Asexual reproduction of ‘NCORNSP-025SCK’ by cuttings has shown that the unique features of the new cultivar are stable and that the plant reproduces true to type in successive generations.